They may pay cash for purchases, but they hand write all the weights behind a curtain. How do you know they are paying for all the weight you brought in? I prefer to have a stamped scale weight on my scrap metals and watch the scale they weigh on.

My girlscout troop got the best price from Zimmerman's for our aluminum can project, my son junked his old car for an unbelieveable amount of money, and I just bring over what ever everyday recycling I have no matter how small. They pay me in cash and are always friendly and polite.